Tank, hollow column support therefor, and method of building the same



April 4, 1939. J, M, WORKMAN TANK, HOLLOW COLUMN SUPPORT THEREFOR, ANDMETHOD OF BUILDING THE SAME Filed Jan. 18, 1936 I Snventor James/llilhfmaiz Patented Apr.4, 1939 I r 2,153,492

UNITED STATES PATENT OFFICE TANK, HOLLOW COLUMN SUPPORT THERE- gOR, ANDMETHOD OF BUILDING THE James Minor Workman, Winnsboro, S. 0. ApplicationJanuary 18, 1936, Serial No. 59,785 Claims. (01. 72-13) The inventionrelates to tanks, hollow column .provided with ring or spiralreinforcements l5 support therefor, and method of building the adjacentthe outer periphery, and I5, adjacent same. the inner periphery of thehollow column;

It is an object of the invention to provide a The hollow column portionis also shown as tank structure which may be constructed with providedwith vertical reinforcements I4 adjacent 5 extreme economy and whichshall be free from the outer rings l5 and desirable extending ratherupkeep and repair costs. deeply into the foundation 3, and shown ascurved The principles involved in the structure of the at its junctionwith the column and extending present invention are an elaboration ofthe inout into the slab to the termination of the column H ventiondescribed in my copending application head.

Serial No. 686,183, filed August 21, 1933, for Con- The form of slabutilized as the bottom of the crete construction, now Patent No.2,035,007, and tank in the structure shown follows the printhe presentinvention comprises a continuation in ciples outlined in my copendingapplication above part of said application. referred to which may bestated briefly as fol- It is an object of the invention to provide alows: by provision of properly designed dimenhollow column shown asutilized as a support for sions of the slab and substantially circularand the tank structure but which is capable of genconcentric reinforcingband elements grouped in eral use as a column. radially spaced groupsalternating between the It is a further object of the invention toprovide pp and lower portions of t s p t y a composite tank structurehaving a novel seal there are developed radial compressive stresses atthe junction of the side and bottom of the and circumferential tensilestresses, the latter tank. occurring in circumferential stress bandsalter- It is a further object of the invention to pronately at the upperand lower portions of the vide a tank structure supported upon a hollowslab.

column utilizing the hollow of the column not While it is preferred touse the principles of only as an intake or outlet from the tank but also'my former application referred to, the invention in the method ofconstructing the same. of the present application is not considered asFurther objects of the invention will appear confined to theseprinciples as other forms of refrom the following description when readin coninforced slab may b utilizednection with the accompanying drawingshowi A difliculty with tanks made wholly of concrete ing illustrativeembodiments of the invention, and is found to be that the differences ofexpansion wherein: between the submerged and non-submerged porv Figure 1is a plan view; tions of the walls introduce destructive force. It Fig.2 is a side elevation partially in central is preferred therefore, andas shown, to make vertical section; the tank a composite structurecomprising a con- Fig. 3 is a detail horizontal section upon an cretebottom and steel or wooden side walls.

enlarged scale of a joint between elements of the When made of steel theside walls may be -walls of the tank; made as indicated in Figure 2 ofvertical plates Fig. 4 is a detail vertical section upon an en- 5desirably welded at their joints and shown as larged scale of the upperrim of the tank; provided with an angle rim 6 bolted thereto by Figs. 5and 6 are detail vertical sections upon bolt i, as shown in Figure 4. anenlarged scale showing structures of the joint A different IOIm of jointbetween the Plates is between the side and bottom of the tank; andindicated in Figure 3 wherein the edge of the Fig. *7 is a like viewshowing another form of other plate is turned outwardly at a 90 angle,composite tank. the bolt hole for bolt 8 being placed sufficiently 5 Asshown, the tank is supported upon a hollow near the outturned portion toprevent revolution column 2 supported upon and preferably integral ofthe bolt when the nut is tightened. The edge with a base 3 andsupporting and preferably inof the remaining plate 5 is shown asdeflected integral with the slab l which serves as the bottom wardlysubstantially at an angle of to provide of the tank. a V-shaped recessin which packing material ll, The foundation 3 is shown as provided withdesirably of some permanently plastic material, ring reinforcements l6,l1, and I8 placed in the as putty, may be placed. It will be seen thatconcrete in the position to conform with the princ the deflected marginsof the plates will provide ciples outlined in my former applicationabove a desirable stiffness to the plates, particularly referred to. Thehollow column is shown as while being handled before assembly,

er packing material is for the purpose of preventing access of moisturewhich, freezing in the space, might cause deterioration of thestructure.

In Figure 6 the slab I is shown as provided with an annular rebate forthe purpose of locating the plates during the construction and thepacking material 9 is shown interiorly only of the joint.

The groove of Figure 5 and the rebate of Figure 6 are not for thepurpose of assisting in prevention of leakage. The packing material 9 issufficient for this purpose since the same adheres to the surfaces andhydraulic pressure will cause a tight joint and efiectually preventleakage.

In Figure '7 is-shoWn a form of composite tank wherein the side walls 5'are formed of wooden staves and leakage is prevented by a packing in theform of a fillet 9. This form of joint between the sidewalls and theslab is equally effectual when the side walls are made of steel platesand it is found that merely the form of packing shown at 9' issufiicient to prevent leakage at the joint without the provision of agroove or rebate. V

I have discovered that a hollow column will support a greater weightthan a solid column of the same diameter if properly reinforced and ifthe hollow of the column is properly proportioned to the totaldiameterof the column. To secure this result, the interior space shouldapproximate one-half of the outer diameter of the column. It is notto beunderstood that the pro portion stated is critical as a part of theadvantage of the invention may be secured by approaching this ratio.

The principle of this discovery is that the natural organization ofstresses in a cylinder is such that the movements propagated in thecentral quarter of the gross area impose a bursting tendency upon theouter shell, so that a column of a given diameter Will have its strengthincreased by the omission of this central core,while the internal ringof the shell preferably should be protected against circumferentialstress (produced by the shell) by the use of the internal spiral [5.

The vertical bars used in conjunction with this inner spiral, if used atall, should be square and placed outside of the spiral.

In accordance with the method of construction provided by the invention,the conduit 4 is first placed at the site of the foundation 3, to beconstructed, desirably initially terminating adjacent the junctionbetween the column and the foundation whereupon concrete is pumpedthrough the conduit 4 to spill over the edge thereof and which may bestruck off with a revolving templet of the form desired for the finishedsurface of the foundation.

When this portion has been placed, forms for the hollow column and forthe slab are placed and the conduit 4 is extended upwardly substantiallyto the upper limit shown in Figure 2.

The pumping of the concrete is then continued, which spilling over theupper edge of the conduit, fills the cylindrical portions of the formand upon continued flow of the concrete, a templet is utilized to berevolved about the center of the structure to-strike off the bearingportion and the upper surface of the slab. Upon completion of theplacing of the concrete, the conduit 4 is cleared of concrete as by useof compressed air or a swab, and is utilized in the use of the tank asfor instance for an intake or an outlet conduit.

In structures where the central hollow of the column is desirably toolarge for efficient delivery of concrete, the invention includes theexpedient of inserting a concrete delivery flexible conduit as of rubberor the like of smaller bore than the hollow of the column, which mayterminate in a washer-like cap to seat upon the upper end of the metalconduit 4 through which the concrete may be pumped.

When the central form ofcolumn is extended upwardly, the hose may bedrawn upwardly to the new position to continue the delivery of theconcrete.

This expedient will enable the use of even lighter metal for the liningof the hollow of the column, and the joints, if any, in the said liningneed not be strictly tight. I

In the case of the use of this last named expedient, a metal lining forthe hollow of the column is not essential and a collapsible andremovable inner form may be used, but in this case the inner reinforcingrings or the outer rings or both may require to be increased in strengthor number to enable the column to support the hydraulic pressure ofliquid within the tank.

The portions of the conduit 4 which are encased in the concrete may beof very light material as they are merely for convenience in the placingof the concrete and in the formation of the hollow portion of thecolumn.

Minor changes may be made in the physical embodiments of the invention,or in the steps of the process, within the scope of the appended claimswithout departing from the spirit of the invention.

I claim:

1. A tank structure comprising, in combination: a foundation; a concretecolumn integral therewith and having a head integral with its shaft; aconcrete slab tank bottom integral at its center portion with saidcolumn head, thinnest adjacent its periphery and widely overhanging andsolely supported by said column; said slab comprising a plurality ofcircumferentially disposed concentric reinforcing elements, saidelements alternating in position relative to the top and bottom of theslab and tank side Walls of assembled preformed elements havingexpansion characteristics differing from concrete seating on said slabadjacent the periphery thereof and free for movement thereon.

2. A tank structure comprising, in combination: a circular foundation; acylindrical column supported on said foundation; said column formed witha central hollow concentric with its axis to increase itsweight-carrying capacity; a concrete slab tank bottom widely overhangingand supported at its central portion upon said column as its sole meansof support; said slab comprising a plurality of circumferentiallydisposed concentric reinforcing elements, said elements alternating inposition relative to the top and bottom of the slab and tank side wallsof assembled preformed elements having expansion characteristicsdiffering from concrete seated upon said slab adjacent its periphery.

3. A tank structure comprising, in combination: a foundation member ahollow column and a tank bottomconcrete slab formed as a monolith; tankside walls of assembled preformed elements having expansioncharacteristics differing from concrete seating freely upon said slabadjacent its periphery; and a packing fillet of substantiallypermanently viscous material at the interior of the joint between theslab and side Walls to seal the joint against leakage.

4. A tank structure comprising, in combination: a foundation memberopening; a hollow column supported on said foundation; the hollow ofsaid column communicating with said opening; a slab tank bottom having acentral opening communicating with the hollow of said column; said slabcentrally supported by and widely overhanging the upper extremity ofsaid column; tank side walls seathaving a central I ing on said slabadjacent its periphery; and a conduit extending from said foundation andcommunicating with its central opening.

5. The method of forming a tank bottom and support therefor whichcomprises: placing a conduit at the site of the structure below thebottom area of'the structure and including an upwardly directed portioncentral of the site; delivering concrete material under pressure throughsaid conduit; and shaping the said material as it overflows from theupper end of said conduit to the form of a foundation, a hollow centralcolumn integral therewith, and a tank bottom slab integral with saidhollow column.

JAMES M. WORKMAN.

